The present invention is directed to a heat dissipation apparatus for portable electronic devices, and more specifically, to a heat dissipation apparatus using heat pipes for a laptop computer.
Increasingly complex integrated circuits for use with computers, and more specifically, with laptop or portable computers, have resulted in numerous known advantages. However, these advantages are not without their corresponding drawbacks, namely, the generation of more heat than computers using less complex integrated circuits. Cooling of heat-producing components within a laptop computer can be critical to avoid excessive amounts of heat buildup which can adversely affect the performance of a microprocessor chip and other electronic components. Several systems are available to attempt to cool the electronic components of a portable computer.
For example, an electric fan placed near heat-generating components can blow hot air away from such components. However there are some drawbacks to using the electric fan. First, the necessity for moving parts in these electric fans makes them susceptible to breakage. Second, the electric fans generate a significant amount of noise. Third, the use of electric fans in portable battery-powered computers, where maximum battery life is desirable, is a drawback since providing power to the electric fan reduces the battery life of the computer. Fourth, the relatively large size of a typical electric fan requires a large amount of space inside the portable computer, where space is at a premium. Fifth, circulation of air into the electric fan also pulls in dust and debris. For at least the foregoing reasons, it would be desirable to provide sufficient heat dissipation away from heat-generating electronic components without the need to use an electric fan.
Another heat dissipation device involves the use of a heat sink. Essentially, the heat sink is placed in thermal communication with the processor or other heat-generating components to transfer heat away from such components into the heat sink. The transferred heat is then dissipated through the surface area of the heat sink, thereby reducing the amount of heat buildup in the electronic components. However, there are some drawbacks to using only heat sinks, especially in portable computers that implement processors which generate a significant amount of heat. First, if a significant amount of heat is generated, then a larger-sized heat sink is necessary to adequately dissipate the amount of heat. Second, larger-sized heat sinks tend to weigh more and take up more space.
A third and relatively new method of dissipating heat from a processor involves the use of a heat pipe. Heat pipes operate by placing an evaporation portion of the heat pipe in thermal communication with a heat-generating electronic component. The second end or condensation portion of the heat pipe is positioned away from the heat-generating component. The heat pipe typically contains a fluid that flows along a wick attached to the inner surface of the pipe. Heat from a heat-generating electronic component vaporizes the fluid which creates a pressure differential between the end of the heat pipe thermally coupled to the heat source and the remote end of the heat pipe. The pressure differential pumps the fluid through the wick from the condensation portion to the evaporation portion. The vaporized fluid is then pumped from the evaporation portion to the condensation portion of the heat pipe. Heat pipes have the potential of rapidly transferring heat away from a microprocessor chip or other heat-generating component. Hence, the use of heat pipes will be desirable in situations when the use of an electric fan or a large heat sink are undesirable.
It is desirable to integrate the use of heat pipes in portable computers in a manner which can be easily manufactured and yet provide reliable and sturdy support for the heat pipe to avoid crimping or other damage thereto. It is further desirable to transfer the heat from the heat-generating components to a large, remote heat sink where the heat will not damage electronic components.